So you want to add models into your CS map. It's pretty easy just putting one in. First you need or should get the Half-Life model viewer. It's free for download on the chUmbaLum sOft site. Then look thru your models in your ctrike/models folder. Find the one you want and write the name of it down if you can't remember it. So lets take mbken's humvee with a daddycool skin on it.(nice looking model)
And let's say we want to add this model in our map. We would make sure this model was in our cstrike/model folder.Then click on the point entity tool.(left hand tool bar)It's the 4th one down or you can hit shift+e (hotkeys for that tool). Looks like this.
Then on the right hand side of WC(VHE)there will be an entity list.Scroll thru them and pick the cycler_sprite entity.Point your mouse in the 3d textured window about where you would want to place it.Left click and it's in. Most times it will have to be adjusted in the wireframe views, so the model is on the ground and not floating in the air or buried in the ground.No way to tell until you compile the map and see how it comes out. (This is where you would do a quick compile(fast vis and no rad)just to see)Most times though you can just put the cycler_sprite square halfway into the ground and it comes out good.
Then in the properties window of the cycler_sprite scroll down to the sprite line And your going to type inmodels/nameofmodel.mdl in this case with mbken's model if the name of it was humvee I would type in models/humvee.mdl . And that's about all there is to adding a model to a map. Easy part.

Now
comes the harder part. Clipping the model so you won't be able to walk
thru it.

You are better off building a little cube of a map for this,since you
will be compilng a few times. For a basic quickie map,just
drag out a decent size cube.Hollow it out.Should kind of look like this.
You can texture it anyway you want.

As
you can see you'll need the 3 things in there.(light_environment.info_player_start,cycler_sprite).
Now you can quickly compile this so you can see how the model sits in
the map.

As you can see the model is half way in the ground.So what you have
to do is
grab the cycler_sprite and move it up some.So
after I moved it and re-compiled
3 times I got it to line up to the ground.

Now the fun part begins.You'll
have to make a brush about the same size you think
the model is. I am using
a metal texture. Then make it a func_wall
and give it the properties of render mode texture
and fx amount
of around 150.And what you will get is a block that you can see
the model and the block.Now
you are going to have to start shaping the brush and more than likely
add more brushes until you get the shape
of the model.I used a total of 7 brushes to basically
outline the model.You can use more or less.This will make
it so you can climb on it and making it a func_wall
will make it so you can't shoot thru it.(with certain guns of course).
Then when you got it all clipped out the way you want it.Take all the
brushes and change the fx amount to 0.This will make the func_walls invisible in the
game.